A child is diagnosed with osteosarcoma. What is the primary treatment for this condition?

Choice A rationale Prolonged immobilization alone is not the primary treatment for osteosarcoma. While immobilization may be used temporarily for symptom management or post-surgically, it does not address the underlying malignant tumor, which requires definitive intervention to prevent local progression and systemic metastasis. Choice B rationale Chemotherapy alone is typically used as an adjunct to primary surgical treatment for osteosarcoma, not as the sole primary treatment. While it plays a crucial role in eradicating micrometastases and improving overall survival rates, it is insufficient to cure the primary tumor without surgical resection. Choice C rationale Radiation therapy is generally less effective than surgery for primary osteosarcoma because the tumor cells are often radioresistant. While it may be used in specific situations, such as for palliative care or when surgical resection is not feasible, it is not the primary curative treatment. Choice D rationale Removal of the bone or limb, often through surgical resection or amputation, is the primary treatment for osteosarcoma. This approach aims to achieve complete macroscopic tumor removal, which is crucial for preventing local recurrence and maximizing the chances of long-term disease-free survival.